Zopiclone is "a cyclopyrrolone derivative...a short-acting hypnotic" that acts as a "hypnotic, sedative, anixolytic, anti-convulsant and muscle-relaxant"; at least that's what it says on the packet!

Prescriptions for this little blue pill have more than doubled since 2000. Today more than 500,000 scripts for zopiclone are handed out every year, making it one of New Zealand's most-prescribed medicines.

John Ashton is a Senior Lecturer in the Department of Pharmacology & Toxicology at the Otago School of Medical Sciences. He looks at what zopiclone does, how it works, why you'd be taking it, and why there are concerns over its use and overuse.